package com.wwinsoft.framework.web;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.opensymphony.xwork2.ModelDriven;
import com.opensymphony.xwork2.Preparable;

/**
 * Struts2中典型CRUD Action的抽象基类.
 * <p/>
 * 主要定义了对Preparable,ModelDriven接口的使用,以及CRUD函数和返回值的命名.
 *
 * @param <T> CRUDAction所管理的对象类型.
 * @author calvin
 */
public abstract class CrudActionSupport<T> extends BaseActionSupport implements ModelDriven<T>, Preparable {

    private static final long serialVersionUID = -1653204626115064950L;

    /**
     * 进行增删改操作后,以redirect方式重新打开action默认页的result名.
     */
    public static final String RELOAD = "reload";

    protected Logger logger = LoggerFactory.getLogger(getClass());

    /**
     * Action函数, 默认的action函数, 默认调用list()函数.
     */
    @Override
    public String execute() throws Exception {
        return list();
    }

    //-- CRUD Action函数 --//

    /**
     * Action函数,显示Entity列表界面. 建议return SUCCESS.
     */
    public abstract String list() throws Exception;

    /**
     * Action函数,显示新增或修改Entity界面. 建议return INPUT.
     */
    @Override
    public abstract String input() throws Exception;

    /**
     * Action函数,新增或修改Entity. 建议return RELOAD.
     */
    public abstract String save() throws Exception;

    /**
     * Action函数,删除Entity. 建议return RELOAD.
     */
    public abstract String delete() throws Exception;

    //-- Preparable函数 --//

    /**
     * 实现空的prepare()函数,屏蔽了所有Action函数都会执行的公共的二次绑定.
     */
    public void prepare() throws Exception {
    }

    /**
     * 定义在input()前执行二次绑定.
     */
    public void prepareInput() throws Exception {
        prepareModel();
    }

    /**
     * 定义在save()前执行二次绑定.
     */
    public void prepareSave() throws Exception {
        prepareModel();
    }

    /**
     * 等同于prepare()的内部函数,供prepardMethodName()函数调用.
     */
    protected abstract void prepareModel() throws Exception;

}
